Allen is right, The U code does =E2=80=8Bnot apply since the material has been through a process and is no longer reagent grade, it=E2=80™s considered a spent. Allen also raises a good point about oxidizing
properties of the solution. You can do a quick and dirty test with potassium iodide starch paper. If it has the D001 characteristic, then it's easy, profile the waste with you disposal facility with a D001&D002 and ship it in bulk.

If it doesn't "OX" and you are seriously considering perform elementary neutralization and releasing this to the sanitary drains, you must consider the ultimate environmental fate (Ol=E2=80™ Man River
in your case and beyond). I'd start with what (SWBNO) & (LADEQ) stipulate on [fluoride and/or nitrate/nitrite] effluents. Consider the need for a lab analytical to document the composition and properties of the waste stream unless you have well documented
generator knowledge. If it is still looking benign and you think the municipality can handle it, maybe send a letter on letterhead to your local municipal water office a letter requesting interpretation and permission to release this material to their system
and see if you get a response. If after all that, it is determined suitable for release to the public sewer, I would be at a comfortable level to put in writing that this stream is suitable to release to the lab drains. If this is long term, it might be worth
doing the work.

On the other hand, some are from the school of thought that lab wastes should never be released to the environment. Also consider the effort to perform neutralization (purchase and store neutralizer,
man hours to neutralize, risk) If using calcium carbonate (marble chips) there can be a considerable standing time for the pH to change. SO, If the material does not OX and this is truly a heavy, regular waste stream that does not change, it can be cost effective
and a sound practice to profile the material with your vendor/end disposal facility and bulk into DOT rated shippable 5, 16, 30, 55 gallon drums. We need to be good stewards of the environment. In the research lab, waste disposal fees are the cost of doing
business.

I work at a semiconductor manufacturer so we use a lot of hydrofluoric acid (annoyingly referred to as 'HF').

First of all, we have a fluoride level permit as administered by city waste water - we can only send a certain amount of fluoride to the city.

What we do to treat our "HF" is send it into a treatment tank with CaCl in order to precipitate out as much of the Fluoride as possible (city waste water does not mind the precipitate).
Then, this treated hydrofluoric acid goes into our acid treatment where we need to monitor the pH before it goes to the city.

Please feel free to get in touch if you have more questions about this process.

It is my understanding that this would not qualify since the hydrofluoric acid is classified as toxic and corrosive. Elementary neutralization can only be performed on wastes that exhibit the corrosivity
characteristic.

A good source for treatment methodologies is Margaret-Ann Armour's book called "Hazardous Laboratory Chemical Disposal Guide".

We have a new project that is generating around 10 gallons of an aqueous solution per week consisting of <1% of hydrofluoric acid and nitric acid that
is being collected and disposed of as hazardous waste. The PI wants to know if he can neutralize this solution and dispose as wastewater. There are two issues at play:

=B7Does this waste qualify under the exemption to treat hazardous waste without a permit? The waste is hazardous because of its corrosivity (D002), and is listed as U134. But does the toxicity of the hydrofluoric
acid, even at these very low concentrations, disqualify it from the treatment exemption?

=B7If it can be treated, is there a widely accepted methodology for neutralization? I have seen multiple procedures either using calcium chloride solutions to bind the fluorine then flocculate into a cake for later
disposal, or using sodium bicarbonate solutions for pH neutralization.

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